The present invention relates to wireless communications networks. In such networks, a geographical area to be covered by the network is divided into cells each being controlled by a node. In existing networks the nodes are represented by Radio Base stations (RBSs), or Node-B as called in 3GPP specifications. Communications to and from a mobile terminal in a cell take place via a node over one or more frequency channels allocated to the cell. A Radio Base station (RBS) in a wideband code division multiple access network (WCDMA), is a part of a Radio Access Network (RAN).
Cells may be of different types. For example macro cells are used in a network to provide large area coverage. Micro cells are deployed in many networks to increase capacity. Within one macro cell coverage area there maybe one or more micro cells.
Hierarchical cellular communications systems employ different size cells to provide both wide-coverage, basic-service (macro cell) and high-quality, high-capacity radio coverage in smaller areas (micro cells). Micro cells are useful in specific areas. For example, micro cells may be located to serve areas of concentrated traffic within the macro cell or to provide a high data rate service. A micro cell uses a low-height antenna and a low base station transmit power which result in a small cell and a short frequency reuse distance, thereby increasing capacity. Additional benefits of a smaller cell include a longer talk-time (battery life time) for users since mobile stations will likely use a substantially lower uplink transmit power to communicate with a micro cell Radio Base station (RBS) than with a base station in a larger macro cell which is likely further away.
In a hierarchical cell structure (HCS), macro cells and micro cells typically overlap to handle different traffic patterns or radio environments. A micro cell base station may be connected to a macro cell base station via digital transmission lines, or the micro cell base station may be treated just like a macro cell and be connected directly to a base station controller node. Such control nodes are a base station controller (BSC), in the well-known global system for mobile communications (GSM) systems, or a radio network controller (RNC), in the third generation, wideband code division multiple access (WCDMA) systems. For more information concerning Macro cells and Micro cells see WO2005057975.
Mobile communications networks are growing rapidly as new cells are introduced into the networks. Currently a geographical position of a base station is manually configured in a control node. However, current way to manually configure the position doesn't work for a home RBS scenario, as end users install their own home RBSs. The end users are also capable of moving home RBSs when moving to or visiting a new location (house, city etc.), without an operator being able, or in many cases willing, to control this. This means that wherever a home RBS is installed and connects to an RNC in a new location, geographical data would need to be updated.
There are many existing systems for positioning of base stations or mobile stations. Patent document US20030148774 relates to a telecommunications system and a method for use in a telecommunications system. The telecommunications system comprises a plurality of service areas, each of the service areas being identified by a service area identifier. In accordance with the method a service area identifier is requested that associates with a mobile station. Upon receipt of the request, one service area identifier is selected from a plurality of possible service area identifiers. A predefined rule for the selection of the service area identifier is used for the selection. Location information that associates with the mobile station is then provided based on the selected service area identifier.
In patent document US2005113117, there is described a cellular communications network where additional control signals comprising virtual base station identification data are distributed in the radio system from well defined locations by e.g. transmitters. Since there is a connection between each virtual base station identification data and the location from where it is transmitted, a mobile terminal can use the information for improving its position estimation according to conventional procedures. No modifications of the mobile terminals are therefore necessary. The mobile terminal is not able to connect to the communications system using the virtual base station identification data, since this data only is intended for position estimating purposes. In such a way, the devices for providing the additional information necessary for the improved position estimation can be made very simple and inexpensive.
Other systems use global positioning system (GPS) receivers for determining positions of Radio Base stations or mobile stations. A GPS receiver has two different problems related to it. First, it adds significantly to the cost of a home RBS. Secondly, GPS normally don't work well indoors due to weak satellite signals.